The present invention relates to a vortex flowmeter capable of measuring very small flow and having an improved anti-vibration characteristics.
There have been various vortex flowmeters for detection of fluid pressure and, among others, a flowmeter in which vortex pressure is transmitted to a pair of chambers partitioned by a diaphragm and vortex pressure is detected as a difference in pressure between the chambers is disclosed in, for example, Japanese Patent Publication No. 3725/1979.
In such conventional flowmeter, in order to detect vortex pressure in a very small flow rate range, the diaphragm partitioning the chambers must be very sensitive. When such highly sensitive diaphragm is used, it may also respond to other forces, such as vibration, than vortex pressure, leading an erroneous detection.